1. Field of the Invention
The present invention relates to magnetic recorders, and more particularly to magnetic recorders of the type in which a magnetic tape contained within a removable cartridge is driven in bidirectional, intermittent fashion to effect digital operation.
2. History of the Prior Art
With the increasing use of magnetic tape recorders in the recording and playback of information in connection with data processing operations, there has been developed a type of tape recorder in which the magnetic tape is completely contained within an enclosed cartridge together with supply and take-up reels and an elastomeric band which rides over a plurality of idlers or rollers. The band is also wrapped around a driven wheel principally contained within but exposed to the outside of the cartridge. Driving of this driven wheel effects driving of the magnetic tape via the elastomeric band. Drive systems of this type enable maintenance of tape tension and tape motion with a single drive motor. In particular, they greatly facilitate the insertion of a reel of magnetic tape into a recording system and the subsequent removal of the tape reel therefrom. Instead of having to load the tape reel onto the recorder and thread the tape through a tortuous path to the opposite reel via a tedious handloading operation or by means of a complex self-threading arrangement, with the tape thereafter being driven under control of a complex arrangement of idlers, rollers or pneumatic devices, one or more capstans with or without pinch rollers and a plurality of tape tensioning devices such as vacuum columns, it is only necessary to slide the cartridge into an operative position within the recorder so that the driven wheel is engaged by a drive wheel and associated motor system contained within the recorder. When it is desired to remove or exchange the tap, the cartridge is readily removed from the recorder by hand, following which the next cartridge is slid into place in like fashion.
While tape recorders of the type utilizing tape cartridges as described above provide a number of notable advantages for certain magnetic tape applications, conventional recorders of that type suffer from a number of disadvantages. One of the more prevalent problems arises from the manner in which the tape cartridge is installed within the recorder. In many systems the cartridge is simply jammed into place in the operative position. The cartridge may be held in the operative position by friction alone or by a rather crude arrangement of elastomeric or spring-loaded devices intended to maintain the cartridge in place. Such mounting systems lack the clear and positive type of action which is frequently desired in such systems. They do not permit the cartridge to be secured in the operative positiotn while substantial pressure is exerted on the driven wheel by the driving system of the recorder. Moreover such arrangements do not lend themselves to positive and automatic ejection of the cartridge upon termination of operation.
A further problem with prior art tape recorders of the tape described relates to the manner in which the driven wheel of the tap cartridge is driven. Many of the prior art systems make use of a pivotably mounted arm which may be spring loaded and which has a motor and associated drive wheel mounted at the free end thereof. The tension of the spring pulls the arm in an appropriate direction so as to engage the drive wheel with the drive wheel of the cartridge when the cartridge is in the operative position. In such arrangements the tension with which the drive wheel is held against the driven wheel of the cartridge is usually limited because of cartridge design considerations. A more serious difficulty arises from the fact that the lever arm mounting of the motor results in resonance which eventually causes a bouncing of the drive wheel with respect to the driven wheel. Further problems arise from the fact that the motor is mounted on the lever arm and therefore plays a substantial role in determining the tension of the drive wheel on the driven wheel. Thus where the recorder assumes one particular orientation, the weight of the motor may increase the tension substantially as compared with other orientations where motor weight is a relatively minor factor.
Accordingly it would be advantageous to provide an arrangement for catching the installed tape cartridge and locking it into operative position in quick and positive fashion. It would, furthermore, be advantageous to provide such an arrangement which would release and partially eject the tape cartridge from the recorder in quick and positive fashion, with such action being performed automatically and electrically where desired.
Further advantages would flow from an arrangement in which the drive wheel is capable of engaging the driven wheel of the cartridge under relatively high tension, and in such fashion that the tension is not affected by factors such as motor weight. Still further advantages would arise from such a system in which undesirable resonant action does not occur so as to interfere with the driving of the driven wheel by the drive wheel.